Add-on combination module for navigation and distance measuring with ultrasound on your DP computer caliper.



With the DP GPS DME module you can navigate and register coordinates with your DP computer caliper and measure distances with the well-known and proven reliable ultrasound technique from Haglöf Sweden. The module is controlled and operated entirely by the computer caliper and its software application. No additional power supply is needed. The module is small and light and does not affect the balance or weight of the computer caliper when assembled on the caliper com-port. 

The DP GPS DME has a 33 channel receiver and supports several different satellite systems such as GPS (US), GLONASS (Russian), Galileo (EU) and GZSS (Japan). The DP GPS DME also supports correction using SBAS: WAAS (American), EGNOS (European) and MSAS (Japanese) which will improve positioning in difficult terrain. The accuracy reaches up to 2.5 m in open terrain, and algorithms predict satellite positions for up to 3 days using data from the latest configurations for up to a month in the DP GPS DME.


The DP GPS DME add-on offers many possibilities depending of software application used in your caliper. You can, for example, position your sample plots, timber stacks, and stock points and individual trees for special research projects. You can make a track log of stock borders or even a whole estate, and have your DP caliper calculate area dimensions. You can navigate to known points with your computer caliper. Transfer coordinates to your DP caliper, for example on test areas or individual trees, and navigate straight to these for inventory and follow-up.

Computer caliper software

The DME function in the DP GPS DME uses ultrasound signals to determine distances and to measure radius in sample plots. With the DME function you can quickly determine if a tree is standing within or outside the sample plot limits. The results are based on a measurement from the tree center to the center of the plot, for extra accuracy. A DP DME module ultrasound system operates with the transponder T3 on a plot staff/monopod.

The DP GPS DME is compatible with DP II (Bios v 2.16 and forward) and the Digitech Professional (Bios v 1.73 and forward). All functions are run through the software application in your caliper.

See also information on the DP GPS module and the DP DME module.

Size 57x30x30mm, 2.28”x1.2”x1.2”.
Weight 25g, 1oz.
Satellite systems Host-based multi-global navigation: GPS(Usa)/GLONASS (Russia)/Galileo(EU)/QZSS(Japan). SBAS Satellite-based augmentation systems: WAAS(USA), EGNOS(EU), GAGAN(India), MSAS(Japan)
Orbit prediction Built in self-generated (Faster TTFF up to 3days)
Geodetic date WGS84
Protocol NMEA. Messages: GGA: Time, position and fix type data
GLL Lat, long, UTC time of position fix and status
GSA GNSS receiver operating mode, satellite used and DOP values
GSV Number of satellites in view ID numbers, elevation, azimuth and SNR values. RMC: Time, date, position, course and speed data.
VTG Course and speed information relative to the ground
Performance data Receiver type 33 tracking/99 acquisition- channel GNSS receiver. Update rate 1Hz (max 10Hz).
Sensitivity Tracking: -165 dBm-. Reacquisition: -160 dBm
Cold starts -147 dBm. Time-To-First-Fix: (All SV @ –130 dBm)
Cold starts 28s up to 15min (open sky)
Warm starts 26s (open sky)
Hot starts <1s (open sky, <2h since last start)
Accuracy Automatic Position. 2.5m CEP (circular error probable) (50% 24 hr static, -130dBm)
Speed 0.1m/s. (50%@30m/s)
Temperature -40° ~+85° C
Electrical data Power supply 2.8~4.3V. Power consumption @ 3.3V (typical)
Acquisition 35mA. Tracking: 30mA. Backup:14uA
  • Built in jamming removing. Built in rechargeable backup memory.
  • DP II requires Bios V2.16 and forward.
  • Digitech Professional I requires Bios V1.73 and forward.